Answer:
Δτ = 50 N.m
Explanation:
The torque applied on an object is given by the product of the force applied on it and the perpendicular distance between the force and the axis of rotation of the object. That is:
τ = F r
where,
τ = Torque applied on the object
F = Force applied on it
r = distance from axis of rotation
<u>FOR HANDLE SIDE OF DOOR</u>:
τ₁ = F r₁
where,
τ₁ = Torque applied on the object = ?
F = Force applied on it = 100 N
r₁ = distance from axis of rotation = 1 m
Therefore,
τ₁ = (100 N)(1 m)
τ₁ = 100 N.m
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<u>FOR MIDDLE OF DOOR</u>:
τ₂ = F r₂
where,
τ₂ = Torque applied on the object = ?
F = Force applied on it = 100 N
r₂ = distance from axis of rotation = 1 m/2 = 0.5 m
Therefore,
τ₂ = (100 N)(0.5 m)
τ₂ = 50 N.m
Now, the difference between the amount of torque in both cases is:
Δτ = τ₁ - τ₂
Δτ = 100 N.m - 50 N.m
<u>Δτ = 50 N.m</u>
Answer: (b)
Explanation:
Given
Mass of box 
Applied force 
Friction force 
Box travels a distance of 
time taken 
Net unbalanced force 
Work done by the unbalanced force
Power developed by unbalanced force
Thus, option (b) is correct.
Answer:
Mass of the wooden Block is 20g.
Explanation:
The buoyant force equation will be used here
Buoyant Force= ρ*g*1/2V Here density used is of water
m*g= ρ*g*1/2V
Simplifying the above equation
2m= ρ*V Eq-1
Also we know from the question that
ρ*V = m + 0.020 Eq-2 ( Density = (Mass+20g)/Volume )
Equating Eq-1 & Eq-2 we get
2m = m+0.020
m = 0.020kg
m = 20g
